In the construction phase of a hydroelectric power plants (HEPP) many negative effects including soil compaction, road construction, modification in flow regime, degradation of aquatic habitats, power transfer lines and roads, and impacts on wildlife are expected on ecosystems. Streams and stream habitats are affected from all these immediately. In our country the dam-type hydro power plant is used heavily where the energy production is closely related to water holding capacity, but this type of energy production give rise to high. Therefore instead of this type of energy production is used of the efforts of different hydraulic evaluation possibilities. This is an example of runoff type hydroelectric power plants which is related to natural flow characteristics during energy producing. With the effect of different energy cost, some changes has been occurred in the energy sources policies (privatization, legislation changes). A useful tool of field surveys together with ecohydrological study is required to reveal these effects and the integration level of the stream. These suggest that a watershed based scientific evaluation that ensures the sustainability of ecosystems is a ecohydrological research gap in our country. An evaluation will be improved to reveal the ecohydrological effects of run-of-river type hydroelectric power plants as an outcome of this study.